W9725G6JB Datasheet, PDF (4/87 Pages) Winbond – 4M  4 BANKS  16 BIT DDR2 SDRAM

W9725G6JB
1. GENERAL DESCRIPTION
The W9725G6JB is a 256M bits DDR2 SDRAM, organized as 4,194,304 words  4 banks  16 bits.
This device achieves high speed transfer rates up to 1066Mb/sec/pin (DDR2-1066) for various
applications. W9725G6JB is sorted into the following speed grades: -18, -25, 25I, 25A, 25K and -3.
The -18 grade parts is compliant to the DDR2-1066 (7-7-7) specification. The -25/25I/25A/25K grade
parts are compliant to the DDR2-800 (5-5-5) or DDR2-800 (6-6-6) specification (the 25I industrial
grade parts which is guaranteed to support -40°C ≤ TCASE ≤ 95°C). The -3 grade parts is compliant to
the DDR2-667 (5-5-5) specification.
The automotive grade parts temperature, if offered, has two simultaneous requirements: ambient
temperature (TA) surrounding the device cannot be less than -40°C or greater than +95°C (for 25A),
+105°C (for 25K), and the case temperature (TCASE) cannot be less than -40°C or greater than +95°C
(for 25A), +105°C (for 25K). JEDEC specifications require the refresh rate to double when TCASE
exceeds +85°C; this also requires use of the high-temperature self refresh option. Additionally, ODT
resistance and the input/output impedance must be derated when TCASE is < 0°C or > +85°C.
All of the control and address inputs are synchronized with a pair of externally supplied differential
clocks. Inputs are latched at the cross point of differential clocks (CLK rising and CLK falling). All
I/Os are synchronized with a single ended DQS or differential DQS- DQS pair in a source
synchronous fashion.
2. FEATURES
 Power Supply: VDD, VDDQ = 1.8 V  0.1V
 Double Data Rate architecture: two data transfers per clock cycle
 CAS Latency: 3, 4, 5, 6 and 7
 Burst Length: 4 and 8
 Bi-directional, differential data strobes (DQS and DQS ) are transmitted / received with data
 Edge-aligned with Read data and center-aligned with Write data
 DLL aligns DQ and DQS transitions with clock
 Differential clock inputs (CLK and CLK )
 Data masks (DM) for write data
 Commands entered on each positive CLK edge, data and data mask are referenced to both edges
of DQS
 Posted CAS programmable additive latency supported to make command and data bus efficiency
 Read Latency = Additive Latency plus CAS Latency (RL = AL + CL)
 Off-Chip-Driver impedance adjustment (OCD) and On-Die-Termination (ODT) for better signal
quality
 Auto-precharge operation for read and write bursts
 Auto Refresh and Self Refresh modes
 Precharged Power Down and Active Power Down
 Write Data Mask
 Write Latency = Read Latency - 1 (WL = RL - 1)
 Interface: SSTL_18
 Packaged in WBGA 84 Ball (8X12.5 mm²), using Lead free materials with RoHS compliant
Publication Release Date: Nov. 29, 2011
-4-
Revision A02